<?php

declare(strict_types=1);

/**
 * SPDX-FileCopyrightText: Sebastian Krupinski <krupinski01@gmail.com>
 * SPDX-License-Identifier: AGPL-3.0-or-later
 */

namespace KTXF\Utile;

use DateTimeImmutable;
use DateTimeInterface;
use DateTimeZone;

final class Timestamp {

	public static function normalize(mixed $value): ?int {
		if ($value instanceof DateTimeInterface) {
			return self::toEpoch($value);
		}

		if (is_int($value)) {
			return $value;
		}

		if (is_float($value)) {
			return (int)$value;
		}

		if (is_string($value)) {
			if (is_numeric($value)) {
				return (int)$value;
			}

			try {
				return self::toEpoch(new DateTimeImmutable($value));
			} catch (\Exception) {
				return null;
			}
		}

		return null;
	}

	public static function toEpoch(DateTimeInterface $moment): int {
		$utcMoment = DateTimeImmutable::createFromInterface($moment)
			->setTimezone(new DateTimeZone('UTC'));
		return ((int)$utcMoment->format('U') * 1000) + (int)$utcMoment->format('v');
	}

	public static function toDateTime(mixed $value): ?DateTimeImmutable {
		if ($value instanceof DateTimeImmutable) {
			return $value;
		}

		if ($value instanceof DateTimeInterface) {
			return DateTimeImmutable::createFromInterface($value);
		}

		if (is_int($value) || is_float($value) || (is_string($value) && is_numeric($value))) {
			$milliseconds = (int)$value;
			$seconds = intdiv($milliseconds, 1000);
			$microseconds = ($milliseconds % 1000) * 1000;
			return DateTimeImmutable::createFromFormat(
				'U u',
				sprintf('%d %06d', $seconds, $microseconds),
				new DateTimeZone('UTC')
			) ?: null;
		}

		if (is_string($value) && trim($value) !== '') {
			try {
				return new DateTimeImmutable($value);
			} catch (\Exception) {
				return null;
			}
		}

		return null;
	}

	public static function toIso8601(int $value): ?string {
		$moment = self::toDateTime($value);
		return $moment?->format('Y-m-d\TH:i:s.v\Z');
	}

}